* [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
@ 2018-10-12 19:29 ` Jeremy Linton
0 siblings, 0 replies; 12+ messages in thread
From: Jeremy Linton @ 2018-10-12 19:29 UTC (permalink / raw)
To: linux-arm-kernel
The BAD_MADT_GICC_ENTRY check is a little too strict because
it rejects MADT entries that don't match the currently known
lengths. We should remove this restriction to avoid problems
if the table length changes. Future code which might depend on
additional fields should be written to validate those fields
before using them, rather than trying to globally check
known MADT version lengths.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
arch/arm64/include/asm/acpi.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 709208dfdc8b..4d0946bd485a 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -22,12 +22,12 @@
#include <asm/tlbflush.h>
/* Macros for consistency checks of the GICC subtable of MADT */
-#define ACPI_MADT_GICC_LENGTH \
- (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
+#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \
+ struct acpi_madt_generic_interrupt, efficiency_class)
#define BAD_MADT_GICC_ENTRY(entry, end) \
- (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
- (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
+ (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
+ (unsigned long)(entry) + (entry)->header.length > (end))
/* Basic configuration for ACPI */
#ifdef CONFIG_ACPI
--
2.14.3
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
2018-10-12 19:29 ` Jeremy Linton
@ 2018-10-15 9:29 ` Sudeep Holla
-1 siblings, 0 replies; 12+ messages in thread
From: Sudeep Holla @ 2018-10-15 9:29 UTC (permalink / raw)
To: Jeremy Linton
Cc: linux-arm-kernel, catalin.marinas, will.deacon, ard.biesheuvel,
james.morse, rafael.j.wysocki, takahiro.akashi,
lorenzo.pieralisi, ahs3, linux-acpi, linux-kernel, Sudeep Holla
On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
> The BAD_MADT_GICC_ENTRY check is a little too strict because
> it rejects MADT entries that don't match the currently known
> lengths. We should remove this restriction to avoid problems
> if the table length changes. Future code which might depend on
> additional fields should be written to validate those fields
> before using them, rather than trying to globally check
> known MADT version lengths.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
> arch/arm64/include/asm/acpi.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 709208dfdc8b..4d0946bd485a 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -22,12 +22,12 @@
> #include <asm/tlbflush.h>
>
> /* Macros for consistency checks of the GICC subtable of MADT */
> -#define ACPI_MADT_GICC_LENGTH \
> - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
> +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \
> + struct acpi_madt_generic_interrupt, efficiency_class)
>
This makes it 76 always which is fine, just that the first user of
efficiency_class should check for the length before accessing it.
No user of efficiency_class yet, so I am fine with this change.
> #define BAD_MADT_GICC_ENTRY(entry, end) \
> - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
> - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
> + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
> + (unsigned long)(entry) + (entry)->header.length > (end))
>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
@ 2018-10-15 9:29 ` Sudeep Holla
0 siblings, 0 replies; 12+ messages in thread
From: Sudeep Holla @ 2018-10-15 9:29 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
> The BAD_MADT_GICC_ENTRY check is a little too strict because
> it rejects MADT entries that don't match the currently known
> lengths. We should remove this restriction to avoid problems
> if the table length changes. Future code which might depend on
> additional fields should be written to validate those fields
> before using them, rather than trying to globally check
> known MADT version lengths.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
> arch/arm64/include/asm/acpi.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 709208dfdc8b..4d0946bd485a 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -22,12 +22,12 @@
> #include <asm/tlbflush.h>
>
> /* Macros for consistency checks of the GICC subtable of MADT */
> -#define ACPI_MADT_GICC_LENGTH \
> - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
> +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \
> + struct acpi_madt_generic_interrupt, efficiency_class)
>
This makes it 76 always which is fine, just that the first user of
efficiency_class should check for the length before accessing it.
No user of efficiency_class yet, so I am fine with this change.
> #define BAD_MADT_GICC_ENTRY(entry, end) \
> - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
> - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
> + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
> + (unsigned long)(entry) + (entry)->header.length > (end))
>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
2018-10-12 19:29 ` Jeremy Linton
@ 2018-11-01 11:31 ` Lorenzo Pieralisi
-1 siblings, 0 replies; 12+ messages in thread
From: Lorenzo Pieralisi @ 2018-11-01 11:31 UTC (permalink / raw)
To: Jeremy Linton
Cc: linux-arm-kernel, catalin.marinas, will.deacon, ard.biesheuvel,
james.morse, rafael.j.wysocki, takahiro.akashi, sudeep.holla,
ahs3, linux-acpi, linux-kernel
On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
> The BAD_MADT_GICC_ENTRY check is a little too strict because
> it rejects MADT entries that don't match the currently known
> lengths. We should remove this restriction to avoid problems
> if the table length changes. Future code which might depend on
> additional fields should be written to validate those fields
> before using them, rather than trying to globally check
> known MADT version lengths.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
> arch/arm64/include/asm/acpi.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
Hi Jeremy,
I assume there is no [PATCH 1/2] (to make sure I have not missed
anything).
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 709208dfdc8b..4d0946bd485a 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -22,12 +22,12 @@
> #include <asm/tlbflush.h>
>
> /* Macros for consistency checks of the GICC subtable of MADT */
> -#define ACPI_MADT_GICC_LENGTH \
> - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
> +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \
> + struct acpi_madt_generic_interrupt, efficiency_class)
I would add a comment explaining why the efficiency_class offset
corresponds to the min length, I will do it myself before sending it
upstream.
I will take this patch and send it to Will/Catalin with ARM64 ACPI
material for v4.21.
Thanks,
Lorenzo
>
> #define BAD_MADT_GICC_ENTRY(entry, end) \
> - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
> - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
> + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
> + (unsigned long)(entry) + (entry)->header.length > (end))
>
> /* Basic configuration for ACPI */
> #ifdef CONFIG_ACPI
> --
> 2.14.3
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
@ 2018-11-01 11:31 ` Lorenzo Pieralisi
0 siblings, 0 replies; 12+ messages in thread
From: Lorenzo Pieralisi @ 2018-11-01 11:31 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
> The BAD_MADT_GICC_ENTRY check is a little too strict because
> it rejects MADT entries that don't match the currently known
> lengths. We should remove this restriction to avoid problems
> if the table length changes. Future code which might depend on
> additional fields should be written to validate those fields
> before using them, rather than trying to globally check
> known MADT version lengths.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
> arch/arm64/include/asm/acpi.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
Hi Jeremy,
I assume there is no [PATCH 1/2] (to make sure I have not missed
anything).
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 709208dfdc8b..4d0946bd485a 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -22,12 +22,12 @@
> #include <asm/tlbflush.h>
>
> /* Macros for consistency checks of the GICC subtable of MADT */
> -#define ACPI_MADT_GICC_LENGTH \
> - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
> +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \
> + struct acpi_madt_generic_interrupt, efficiency_class)
I would add a comment explaining why the efficiency_class offset
corresponds to the min length, I will do it myself before sending it
upstream.
I will take this patch and send it to Will/Catalin with ARM64 ACPI
material for v4.21.
Thanks,
Lorenzo
>
> #define BAD_MADT_GICC_ENTRY(entry, end) \
> - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
> - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
> + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
> + (unsigned long)(entry) + (entry)->header.length > (end))
>
> /* Basic configuration for ACPI */
> #ifdef CONFIG_ACPI
> --
> 2.14.3
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
2018-11-01 11:31 ` Lorenzo Pieralisi
@ 2018-11-01 14:22 ` Sudeep Holla
-1 siblings, 0 replies; 12+ messages in thread
From: Sudeep Holla @ 2018-11-01 14:22 UTC (permalink / raw)
To: Lorenzo Pieralisi
Cc: Jeremy Linton, linux-arm-kernel, catalin.marinas, will.deacon,
ard.biesheuvel, james.morse, rafael.j.wysocki, takahiro.akashi,
Sudeep Holla, ahs3, linux-acpi, linux-kernel
On Thu, Nov 01, 2018 at 11:31:36AM +0000, Lorenzo Pieralisi wrote:
> On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
> > The BAD_MADT_GICC_ENTRY check is a little too strict because
> > it rejects MADT entries that don't match the currently known
> > lengths. We should remove this restriction to avoid problems
> > if the table length changes. Future code which might depend on
> > additional fields should be written to validate those fields
> > before using them, rather than trying to globally check
> > known MADT version lengths.
> >
> > Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> > ---
> > arch/arm64/include/asm/acpi.h | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
>
> Hi Jeremy,
>
> I assume there is no [PATCH 1/2] (to make sure I have not missed
> anything).
>
IIRC, it's a patch fixing module device table entry for SPE. They are
independent, just happened to be put out together.
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
@ 2018-11-01 14:22 ` Sudeep Holla
0 siblings, 0 replies; 12+ messages in thread
From: Sudeep Holla @ 2018-11-01 14:22 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Nov 01, 2018 at 11:31:36AM +0000, Lorenzo Pieralisi wrote:
> On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
> > The BAD_MADT_GICC_ENTRY check is a little too strict because
> > it rejects MADT entries that don't match the currently known
> > lengths. We should remove this restriction to avoid problems
> > if the table length changes. Future code which might depend on
> > additional fields should be written to validate those fields
> > before using them, rather than trying to globally check
> > known MADT version lengths.
> >
> > Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> > ---
> > arch/arm64/include/asm/acpi.h | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
>
> Hi Jeremy,
>
> I assume there is no [PATCH 1/2] (to make sure I have not missed
> anything).
>
IIRC, it's a patch fixing module device table entry for SPE. They are
independent, just happened to be put out together.
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
2018-10-12 19:29 ` Jeremy Linton
@ 2018-11-27 15:01 ` Lorenzo Pieralisi
-1 siblings, 0 replies; 12+ messages in thread
From: Lorenzo Pieralisi @ 2018-11-27 15:01 UTC (permalink / raw)
To: Jeremy Linton
Cc: linux-arm-kernel, catalin.marinas, will.deacon, ard.biesheuvel,
james.morse, rafael.j.wysocki, takahiro.akashi, sudeep.holla,
ahs3, linux-acpi, linux-kernel
On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
> The BAD_MADT_GICC_ENTRY check is a little too strict because
> it rejects MADT entries that don't match the currently known
> lengths. We should remove this restriction to avoid problems
> if the table length changes. Future code which might depend on
> additional fields should be written to validate those fields
> before using them, rather than trying to globally check
> known MADT version lengths.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
> arch/arm64/include/asm/acpi.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
Hi Jeremy,
as mentioned, I added a comment to the macro so that in the future
we will be able to remember the logic behind it.
I pushed the commit out:
git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git acpi/madt
Please have a look, if I hear no objections I shall be sending it to
Will and Catalin to queue it for v4.21.
Thanks,
Lorenzo
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 709208dfdc8b..4d0946bd485a 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -22,12 +22,12 @@
> #include <asm/tlbflush.h>
>
> /* Macros for consistency checks of the GICC subtable of MADT */
> -#define ACPI_MADT_GICC_LENGTH \
> - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
> +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \
> + struct acpi_madt_generic_interrupt, efficiency_class)
>
> #define BAD_MADT_GICC_ENTRY(entry, end) \
> - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
> - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
> + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
> + (unsigned long)(entry) + (entry)->header.length > (end))
>
> /* Basic configuration for ACPI */
> #ifdef CONFIG_ACPI
> --
> 2.14.3
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
@ 2018-11-27 15:01 ` Lorenzo Pieralisi
0 siblings, 0 replies; 12+ messages in thread
From: Lorenzo Pieralisi @ 2018-11-27 15:01 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
> The BAD_MADT_GICC_ENTRY check is a little too strict because
> it rejects MADT entries that don't match the currently known
> lengths. We should remove this restriction to avoid problems
> if the table length changes. Future code which might depend on
> additional fields should be written to validate those fields
> before using them, rather than trying to globally check
> known MADT version lengths.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
> arch/arm64/include/asm/acpi.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
Hi Jeremy,
as mentioned, I added a comment to the macro so that in the future
we will be able to remember the logic behind it.
I pushed the commit out:
git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git acpi/madt
Please have a look, if I hear no objections I shall be sending it to
Will and Catalin to queue it for v4.21.
Thanks,
Lorenzo
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 709208dfdc8b..4d0946bd485a 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -22,12 +22,12 @@
> #include <asm/tlbflush.h>
>
> /* Macros for consistency checks of the GICC subtable of MADT */
> -#define ACPI_MADT_GICC_LENGTH \
> - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
> +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \
> + struct acpi_madt_generic_interrupt, efficiency_class)
>
> #define BAD_MADT_GICC_ENTRY(entry, end) \
> - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
> - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
> + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
> + (unsigned long)(entry) + (entry)->header.length > (end))
>
> /* Basic configuration for ACPI */
> #ifdef CONFIG_ACPI
> --
> 2.14.3
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
2018-11-27 15:01 ` Lorenzo Pieralisi
@ 2018-11-27 16:32 ` Jeremy Linton
-1 siblings, 0 replies; 12+ messages in thread
From: Jeremy Linton @ 2018-11-27 16:32 UTC (permalink / raw)
To: Lorenzo Pieralisi
Cc: linux-arm-kernel, catalin.marinas, will.deacon, ard.biesheuvel,
james.morse, rafael.j.wysocki, takahiro.akashi, sudeep.holla,
ahs3, linux-acpi, linux-kernel
Hi Lorenzo,
On 11/27/2018 09:01 AM, Lorenzo Pieralisi wrote:
> On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
>> The BAD_MADT_GICC_ENTRY check is a little too strict because
>> it rejects MADT entries that don't match the currently known
>> lengths. We should remove this restriction to avoid problems
>> if the table length changes. Future code which might depend on
>> additional fields should be written to validate those fields
>> before using them, rather than trying to globally check
>> known MADT version lengths.
>>
>> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
>> ---
>> arch/arm64/include/asm/acpi.h | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> Hi Jeremy,
>
> as mentioned, I added a comment to the macro so that in the future
> we will be able to remember the logic behind it.
It all looks good to me, Thanks!
>
> I pushed the commit out:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git acpi/madt
>
> Please have a look, if I hear no objections I shall be sending it to
> Will and Catalin to queue it for v4.21.
>
> Thanks,
> Lorenzo
>
>> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
>> index 709208dfdc8b..4d0946bd485a 100644
>> --- a/arch/arm64/include/asm/acpi.h
>> +++ b/arch/arm64/include/asm/acpi.h
>> @@ -22,12 +22,12 @@
>> #include <asm/tlbflush.h>
>>
>> /* Macros for consistency checks of the GICC subtable of MADT */
>> -#define ACPI_MADT_GICC_LENGTH \
>> - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
>> +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \
>> + struct acpi_madt_generic_interrupt, efficiency_class)
>>
>> #define BAD_MADT_GICC_ENTRY(entry, end) \
>> - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
>> - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
>> + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
>> + (unsigned long)(entry) + (entry)->header.length > (end))
>>
>> /* Basic configuration for ACPI */
>> #ifdef CONFIG_ACPI
>> --
>> 2.14.3
>>
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 2/2] arm64: acpi: Prepare for longer MADTs
@ 2018-11-27 16:32 ` Jeremy Linton
0 siblings, 0 replies; 12+ messages in thread
From: Jeremy Linton @ 2018-11-27 16:32 UTC (permalink / raw)
To: linux-arm-kernel
Hi Lorenzo,
On 11/27/2018 09:01 AM, Lorenzo Pieralisi wrote:
> On Fri, Oct 12, 2018 at 02:29:37PM -0500, Jeremy Linton wrote:
>> The BAD_MADT_GICC_ENTRY check is a little too strict because
>> it rejects MADT entries that don't match the currently known
>> lengths. We should remove this restriction to avoid problems
>> if the table length changes. Future code which might depend on
>> additional fields should be written to validate those fields
>> before using them, rather than trying to globally check
>> known MADT version lengths.
>>
>> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
>> ---
>> arch/arm64/include/asm/acpi.h | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> Hi Jeremy,
>
> as mentioned, I added a comment to the macro so that in the future
> we will be able to remember the logic behind it.
It all looks good to me, Thanks!
>
> I pushed the commit out:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git acpi/madt
>
> Please have a look, if I hear no objections I shall be sending it to
> Will and Catalin to queue it for v4.21.
>
> Thanks,
> Lorenzo
>
>> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
>> index 709208dfdc8b..4d0946bd485a 100644
>> --- a/arch/arm64/include/asm/acpi.h
>> +++ b/arch/arm64/include/asm/acpi.h
>> @@ -22,12 +22,12 @@
>> #include <asm/tlbflush.h>
>>
>> /* Macros for consistency checks of the GICC subtable of MADT */
>> -#define ACPI_MADT_GICC_LENGTH \
>> - (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
>> +#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \
>> + struct acpi_madt_generic_interrupt, efficiency_class)
>>
>> #define BAD_MADT_GICC_ENTRY(entry, end) \
>> - (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
>> - (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end))
>> + (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \
>> + (unsigned long)(entry) + (entry)->header.length > (end))
>>
>> /* Basic configuration for ACPI */
>> #ifdef CONFIG_ACPI
>> --
>> 2.14.3
>>
^ permalink raw reply [flat|nested] 12+ messages in thread